(1) Field of the Invention
The present invention relates to pattern recognition systems in general. Specifically, the present invention relates to continuously adapting a pattern recognition system to better resemble an input source.
(2) Prior Art
Many speech recognition systems utilizing known speech references are currently known in the art. In many of these systems no adaptation of the system to an input voice takes place of any kind. That is, many systems contain a set of known references to which the input speech is compared, however these systems do not employ any means for adapting these known references to the individual speaker or the speaker's acoustic environment. Other systems do not employ the concept of a correct reference being associated with the input speech and therefore adaptation of a known speech reference to an individual speaker is not possible.
Some speech recognition systems do provide a limited amount of adaptation of the system to the individual. This limited adaptation usually consists of a step requiring the speaker to read several test sentences into the system thereby allowing, the system to compute a transformation between the speaker's data (i.e., voice characteristics) and the reference data (i.e., reference voice characteristics). Such limited adaptation, however, has several drawbacks. First, it requires each new speaker to the system to read the test sentences before using the system. This reduces the speed of the system and increases the hassle to the individuals. Second, it does not allow for any adaptation after the initial transformation is computed. This shortcoming significantly reduces the effectiveness of the system because the system cannot adapt to changing conditions. For example, after a continuous period of speech, a speaker may become tired. The speaker's tone and speed would change along with his or her mood change, thereby making the original transformation less and less effective.
The present invention solves these and other problems. The present invention requires no reading of test sentences to create a transformation. The present invention system is ready to receive input from a new speaker as soon as the speaker is ready to commence speaking. The present invention also continuously adapts to its acoustic environment. That is, it continuously adapts to changing moods of the speaker or any other changes in the speaker's voice. Furthermore, the present invention adapts to changing background noise and is therefore able to better understand the speaker when background noise increases while the system is being used.
Accordingly, it is an object of the present invention to provide an efficient speech recognition system that adapts to its acoustic environment. It is further an object of the present invention to provide such a speech recognition system operable in a general purpose desktop computer system. It is yet another object of the present invention to provide a speech or pattern recognition system that requires no test input before becoming trained to a particular input voice but rather adapts as the unknown voice is presented. These and other objects not specifically mentioned above will become clear upon discussions of the present invention to follow.